Reconfigurable Multi-Stream Processor for Multiple-Input Multiple-Output (MIMO) Wireless Networks

1. A configurable network adapter comprising: a plurality of N analog front end signal processors, each comprising a transmitter accepting an input signal, a receiver generating an output signal, and an antenna port; said N being an integer greater than 1; a Multiple Input Multiple Output (MIMO) equalizer having a first mode for N inputs and a second mode for less than N inputs; a MIMO modulator having a first mode for generating N outputs and a second mode for generating less than N outputs; a Single Input Single Output (SISO) equalizer having an input and an output; a SISO modulator having an input and an output; a first outer receiver coupled to said MIMO equalizer output, said first outer receiver coupled to the input of a first Media Access Controller (MAC); a first outer transmitter coupled from the output of said first MAC to said MIMO modulator input; a second outer receiver having an input coupled to said SISO equalizer and an output coupled to a second MAC; a second outer transmitter having an input coupled to an output of said second MAC and an output coupled to said SISO modulator input; where in a first mode of operation, each of said N analog front end signal processor transmitter signal inputs are coupled to one of said MIMO modulator outputs and each of said N analog front end signal processor receiver signal outputs are coupled to one of said MIMO equalizer inputs, said configurable network adapter thereby generating M streams of data for an N×M MIMO stream; and in a second mode of operation, each of N−1 of said N analog front end signal processor transmitter signal inputs are coupled to one of said MIMO modulator outputs and an Nth said analog front end transmitter signal input is coupled to said SISO modulator output, and each of N−1 of said analog front end signal processor receiver signal outputs are coupled to one of said MIMO equalizer inputs, and the Nth receiver signal output is coupled to said SISO equalizer input, said configurable network adapter thereby generating M−1 streams of data for an (N−1)×(M−1) MIMO stream; said MIMO equalizer and said MIMO modulator operative on N front end signal processors in said first mode and operative on N−1 analog front end signal processors in said second mode, said SISO equalizer not operative in said first mode and operative on one analog front end signal processor in said second mode.

2. The configurable network adapter of claim 1 where said N is 3.

3. The configurable network adapter of claim 1 where said N is 4.

4. The configurable network adapter of claim 1 where said N=4 and in said first mode, said MIMO equalizer is operative on at least one of a 4×4, 4×3, 4×2, or 4×1 MIMO stream, and in said second mode, said MIMO equalizer is operative on at least one of a 3×3, 3×2, or 3×1 MIMO stream.

5. The configurable network adapter of claim 1 where said N=3 and in said first mode, said MIMO equalizer is operative on at least one of a 3×3, 3×2, or 3×1 MIMO stream, and in said second mode, said MIMO equalizer is operative on at least one of a 2×2 or 2×1 MIMO stream.

6. The configurable network adapter of claim 1 where, in said second mode, said SISO modulator and said second MAC are operative for either a Personal Area Network (PAN) or Wireless Local Area Network (WLAN).

7. The configurable network adapter of claim 1 where, when N=4, in said first mode, said MIMO modulator is operative on at least one of a 4×4, 4×3, 4×2 or 4×1 MIMO stream, and in said second mode, said MIMO modulator is operative on at least one of a 3×3, 3×2, or 3×1 MIMO stream.

8. The configurable network adapter of claim 1 where, when N=3, in said first mode, said MIMO modulator is operative on at least one of a 3×3, 3×2, or 3×1 MIMO stream, and in said second mode, said MIMO modulator is operative on at least one of a 2×2 or 2×1 MIMO stream.

9. The configurable network adapter of claim 1 where, when said N−1 analog front end signal processor transmitters are operative on the same frequency channel as the remaining analog front end signal processor transmitter, and either said MIMO modulator or said SISO modulator is operative as a Personal Area Network (PAN), the analog front end signal processor transmitter associated with said PAN is operative with a reduced power level compared to the analog front end signal processor transmitter not associated with said PAN.

10. The configurable network adapter of claim 1 where said network adapter changes from said first mode to said second mode following a beacon interval during which transmit buffer queues are emptied by transmitting pending Wireless Local Area Network (WLAN) or Personal Area Network (PAN) frames.

11. The configurable network adapter of claim 1 where said network adapter is operative in said first mode during a first interval of a beacon interval and operative in said second mode during a subsequent interval of said beacon interval.

12. A configurable multi-stream Multiple Input Multiple Output (MIMO) stream processor for N channels, N being an integer greater than 2, the MIMO processor comprising: N analog front end signal processors, each said analog front end signal processor having a transmit channel and a receive channel; a MIMO equalizer operative in one of two modes, a first mode where said MIMO equalizer is coupled to said N receive channels, and a second mode where said MIMO equalizer is coupled to a subset N−1 of said receive channels, the Nth receive channel coupled to a SISO equalizer; a MIMO modulator coupled to said N transmit channels in said first mode and coupled to a subset N−1 of said N transmit channels in said second mode; a SISO modulator coupled to one of said transmit channels in said second mode; a SISO equalizer coupled to one of said receive channels in said second mode, wherein during one segment of a beacon interval, said MIMO equalizer and said MIMO modulator are enabled and said SISO equalizer and said SISO modulator are not enabled, and during a different segment of said beacon interval, said MIMO equalizer, said MIMO modulator, said SISO equalizer, and said SISO modulator are enabled.

13. The MIMO processor of claim 12 where, in said first mode, said MIMO equalizer or said MIMO modulator is operative to generate M streams of data in an N×M MIMO mode, where said N×M MIMO mode is at least one of a 4×4, 4×3, 4×2, 4×1, 3×3, 3×2, or 3×1 MIMO mode.

14. The MIMO processor of claim 12 where, in said second mode, said MIMO equalizer or said MIMO Modulator is operative to generate M−1 streams of data from said N−1 receive or transmit channels, thereby generating an (N−1)×(M−1) MIMO stream, including in at least one of a 2×1 MIMO stream or a 2×2 MIMO stream.

15. The MIMO processor of claim 12 where said MIMO equalizer or said MIMO modulator change from said first mode to said second mode during a beacon interval.

16. The MIMO processor of claim 12 where said MIMO equalizer or said MIMO modulator is operative according to IEEE Wireless Local Area Network (WLAN) Standard 802.11n.

17. The MIMO processor of claim 12 where said SISO equalizer or said SISO modulator is operative as either a Wireless Local Area Network (WLAN) or a Personal Area Network (PAN).

18. The MIMO processor of claim 12 where said SISO equalizer is periodically operative during an interval of said second segment and polling for a WLAN device that may be present.